What Is Certified Mail in Japan
"Naiyou shoumei" (内容証明) is registered mail through Japan Post that officially certifies "when, who sent what content to whom." Widely used as legally-grounded warnings, it's highly effective for stopping nuisance calls. Combined with delivery confirmation, it proves the date the recipient received the document - solid evidence in later litigation. Legal practice primers are useful background.
When Certified Mail Is Effective
- Persistent sales calls: Cite Article 17 of the Specified Commercial Transactions Act (no re-solicitation)
- Stalking calls: Send as a warning under the Anti-Stalking Act
- Malicious complainers: Warn about conduct that may rise to obstruction of business or threats
- Unauthorized call recordings: Warn about privacy violations
- Bogus billing: Notify of non-existence of the alleged debt
Preparation Before Sending
1. Identify the recipient
For individuals, you need the address and name. For corporations, the headquarters address and corporate/representative name. Corporate info is verifiable through online corporate registries. For sales calls, research the named company and representative online.
2. Organize evidence
Document call dates, content, and frequency in chronological order. If you have call recordings, prepare transcripts that can be attached.
3. Document structure
Include these elements:
- Sender's address and name
- Recipient's address and name
- Subject line
- Specific facts (when, who, what)
- Legal basis (relevant articles)
- Demand (cease re-solicitation, damages, etc.)
- Response deadline
- Action if non-compliant (litigation, criminal complaint)
- Date and signature
Template: Sales-Call Cessation Demand
Notice [Sender's address] [Sender's name] (seal) [Recipient's address] [Recipient company] [Representative name] Subject: Demand to cease phone solicitations Mr./Ms. ___ of your company has, since [date], placed [N] calls to my number (XXX-XXXX-XXXX) soliciting purchase of ___. On [date], during such a call, I clearly expressed "no intent to contract" and "no further calls necessary." This conduct violates Article 17 of the Specified Commercial Transactions Act (no re-solicitation). I demand cessation of all phone solicitations from your company upon receipt. If solicitations resume within 7 days of receipt, I will report to the Consumer Affairs Agency and METI, and pursue civil damages. [Date]
How to Send
You can submit at a post office counter or use "e-naiyou-shoumei" (online creation and submission) - 24/7, no printing or mailing on your part. Standard cost: postage 84 yen + content certification 480 yen + general registration 480 yen + delivery confirmation 350 yen ≈ 1,400 yen. Each additional page adds 290 yen.
Effectiveness and Limits
Expected effects
- Legitimate operators stop ~90% of the time
- Decisive evidence in later litigation or criminal complaints
- Establishes the fact that you warned them
- Strong pressure recognizing legal risk
Limits
- Limited effect on scam groups or anti-social forces (their listed contacts may be fake)
- Can't be sent if you can't identify the recipient's address
- The mail is a "warning" with no inherent enforcement
- Non-compliance requires separate litigation
If They Don't Comply
If they ignore certified mail, escalate in stages:
- Report to the consumer hotline 188
- File with the Consumer Affairs Agency or METI
- Consult police #9110
- Small claims court (single-day judgment for damages up to 600,000 yen)
- Full civil litigation (consolation damages)
Certified mail is a first-stage warning. Against truly malicious actors, escalate sequentially through administrative channels, criminal complaints, and civil litigation.
Hiring an Attorney
If self-drafting feels risky, the recipient is large, or damages are substantial, hire an attorney. Attorney-signed certified mail carries significantly more psychological pressure and improves compliance rates. As covered in attorney consultation for phone harassment, consultation runs about 5,500 yen per 30 minutes, and certified mail drafting fees range 30,000-100,000 yen.